ObserverList::HasObserver now takes a const pointer.

chrome/browser/chromeos/settings/device_settings_test_helper.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_SETTINGS_TEST_HELPER_H_
 #define CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_SETTINGS_TEST_HELPER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 69 matching lines @@
                                             const std::string& policy_blob) {
     device_local_account_policy_[id].policy_blob_ = policy_blob;
   }
 
   // SessionManagerClient:
   virtual void Init(dbus::Bus* bus) override;
   virtual void SetStubDelegate(SessionManagerClient::StubDelegate* delegate)
       override;
   virtual void AddObserver(Observer* observer) override;
   virtual void RemoveObserver(Observer* observer) override;
-  virtual bool HasObserver(Observer* observer) override;
+  virtual bool HasObserver(const Observer* observer) const override;
   virtual void EmitLoginPromptVisible() override;
   virtual void RestartJob(int pid, const std::string& command_line) override;
   virtual void StartSession(const std::string& user_email) override;
   virtual void StopSession() override;
   virtual void StartDeviceWipe() override;
   virtual void RequestLockScreen() override;
   virtual void NotifyLockScreenShown() override;
   virtual void NotifyLockScreenDismissed() override;
   virtual void RetrieveActiveSessions(
       const ActiveSessionsCallback& callback) override;
@@ skipping 92 matching lines @@
 
   scoped_ptr<DBusThreadManagerSetter> dbus_setter_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DeviceSettingsTestBase);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SETTINGS_DEVICE_SETTINGS_TEST_HELPER_H_